LibWeb: Resolve viewport-relative <img sizes> values

We still don't know how to resolve font-relative lengths in <img sizes>
since we don't always have font size information available at this stage
in the pipeline, but we can at least handle viewport-relative lengths.

This fixes an issue on many websites where low-resolution images were
loaded (appropriate for a small viewport) even when the viewport is big.
This commit is contained in:
Andreas Kling 2023-08-21 12:51:02 +02:00
parent ae5313d33c
commit 0103940cee
Notes: sideshowbarker 2024-07-17 11:34:34 +09:00
4 changed files with 25 additions and 1 deletions

View file

@ -0,0 +1,6 @@
<!doctype html>
<img
src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVQIW2NgaGD4DwAChAGAZM0bBgAAAABJRU5ErkJggg=="
width="400"
height="400"
/>

View file

@ -0,0 +1,10 @@
<!doctype html>
<img
sizes="100vw"
srcset="
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVQIW2P4z8DwHwAFAAH/F1FwBgAAAABJRU5ErkJggg== 100w,
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVQIW2NgaGD4DwAChAGAZM0bBgAAAABJRU5ErkJggg== 200w
"
width="400"
height="400"
/>

View file

@ -1,4 +1,5 @@
{
"img-srcset-viewport-relative-sizes.html": "img-srcset-viewport-relative-sizes-ref.html",
"square-flex.html": "square-ref.html",
"separate-borders-inline-table.html": "separate-borders-ref.html",
"opacity-stacking.html": "opacity-stacking-ref.html",

View file

@ -388,8 +388,15 @@ void SourceSet::normalize_source_densities(DOM::Element const& element)
{
// 1. Let source size be source set's source size.
auto source_size = [&] {
if (!m_source_size.is_calculated())
if (!m_source_size.is_calculated()) {
// If the source size is viewport-relative, resolve it against the viewport right now.
if (m_source_size.value().is_viewport_relative()) {
return CSS::Length::make_px(m_source_size.value().viewport_relative_length_to_px(element.document().viewport_rect()));
}
// FIXME: Resolve font-relative lengths against the relevant font size.
return m_source_size.value();
}
// HACK: Flush any pending layouts here so we get an up-to-date length resolution context.
// FIXME: We should have a way to build a LengthResolutionContext for any DOM node without going through the layout tree.